Inverted incandescent mantle.



c. K. HARDING. INVERTED INGANDESGENT MANTLE. APPLICATION FILED JAN. 21,1910.

960,63. Patented June 7,1910.

money by PATEN FFICE.

, CHARLES KNOX,HARDINGI, OF. CHICAGO, ILLINOIS.

INVERTED INCANDESCENT MANTLE.

9 Specification of Letters Patent. Application filed January 21, 1910.Serial No.

Patented June 7, 1910.

To all whom it may concern:

' Be it known that I, CHARLES KNOX HARD- ING, 'a citizen of the residentof VVoodlawn, city of Chicago, county of Cook, State of Illinois, haveinvented certain new and useful Improvements in Inverted IncandescentMantles, of which the following is a specification.

The invention relates generally to incandescent structures for lightingmade by what is generally known as the Welsbach process which consistsof impregnating a knitted fabric of cotton with solutionsof therefractory earths which are to constitute the finished mantle. Thedimensions of this impregnated fabric areusually more than'100 per cent.greater than that of'the finished product after the cellulose andothervolatile matter has been burned out. But this large structure isfashioned and formed approximately to such shape as will produce thedesired form of the finished mantle after it has been shrunken.

My invention relates particularly to an improved construction ofinverted mantles which have a cylindrical body portion and asemispherical closed end portion which is usually the lower end, and anopen'end through which the flame is applied Prior to my invention,inverted mantles have generally been made from tubular knitted fabricand the closed end most commonly formed by the methods known asgathering and goring. In the former case the lower end is formed bygathering the lower edge of the tube and drawing it to the center. Thisresulted in a thickening or bunching of the goods at and around thecenter of the lower portion of the mantle. This is objc tionablcconsidering that the central zone of the lower portion of an invertedmantle-"1s ar'j particularly valuable area and should not be preventedfrom reaching its highest efliany obstructions or thickenmg at thatpoint. To obviate this, especially for heavier mantles made of coarserthread, goring has been employed; that is, from two to siX curved seamshave been sewn through two adjacent layers of fabric from a point abovethe bottom where the diameter was to be retained to a point in thecentral axis at the bottom. These gores permit a quantity of the stockto be cut out, but the seams themselves interfere with the incandescenceat the central point, which is the most abun- United States, and adantly supplied with gas from its most favorable location in the centerof the flame.

Among the objects of my invention is to produce an inverted mantle ofmore symmetrical shape and having a large area around the'centralsection of its-lower portion consisting of a uniform thickness of fabricwithout seams whereby this most useful portion of an inverted mantle canbe uniformly and entirelyraised to the highest incandescence.

To attain this and other ends features of construction, the arrangementand configuration of theseveral parts, as will appear hereinafter morefully described .and claimed and shown in the accompanying drawings,which illustrate forms of man tles embodying my invention and in whichFigure 1 shows a front elevation of a short length of tubular fabricsevered on a curved "line and forming the segment shaped projections B-Bdependin Fig. 2 is a plan view il ustrating a double segment shapedpiece of single' thickness fabric which is to form a considerable partof the semispherical end portion of the completed mantle. Fig. 3 showsthe upper tubular portion A andcthe single thickness section C, unitedat its edges with the lower depending edges of the tubular fabric A, bya seam 0. Fig. 4 is a section taken on line 44 of Fig. 1. Fig. 5 is asection taken on line 5-5 of Fig. 3. Fig. 6 is a perspective view of afinished fabric mantle, made in accordance with my invention and foldedin a way that may be employed where it is intended to be placed in a Hatenvelop for the market. Fig. 7 is a section taken on line 7'"7 of Fig.6. Fig. 8 shows a side elevation of a finished burned off mantleattached to a carrying ring and indicates one View of the portion formedfrom the section C and illustrates the position of the seam c. p

I do'not wish to confine my invention to the precise shapes or relativesize of what I haveshown in the drawings.

The section referred to as the double segment shaped section may closelyapproximate the outline of an ellipse and in general a variety of ovalshapes might be employed and referred'to as ovals or ellipses, but it isnecessary to produce the best results in the finished mantle as well asto facilitate their manufacture to have the respective edges which areto be united by the seam of as I employ the at its lower end. 7

nearly the same length and configuration as possible.

Asillu'strated in the drawin s, the segment shaped projections B-B, let. attached to the tubular portion, correspond in size, shape and lineardimensions of its curved edge to one of the segment shaped halves of thesection O. In this precise construction the section C would constitute athe semispherical closed end of t e'mantle a roximating a quarter of asphere, but to ma e proper allowance for the difference in the amount ofshrinkage of knitted fabrics in a "lineal and transverse direction, theshape of the section Cas well as the configuration of the dependingsegments BB- may bevaried in such a way that the three when seamedtogether, will constitute an approximately semlspherical bottom portion1n the finished burned out mantle, while in the fabric mantle it ma bedesirable to provide somewhat greater ineal dimensions in the directionof the greatest shrinkage.

Having now described one embodiment of my invention, what I claim is:

1. An inverted fabric mantle consistin of an open topped body portion oftubular abin of a double segment shaped section of fa ric united to theaforesaid segment shaped projections by a seam extending ortion ofceases around the circumference of the doiiblesegi:

cylindrical body portion constructed of a tubular fabric having twocurved segments dependin from its lower end and a double segment s apedsection of a single thickness of fabric having its circumferenceattached to the two curved edges of-the dependin segments whereby asemispherical shaped closed lower end of the mantle is formed by saiddouble segment shaped section and said two depending segments.

3. An inverted mantle consisting of an open topped body portion oftubular knitted fabric and having two segment shaped projections fromits lower end, said lower end being closed by a double segment shapedsection of a single thickness of mantle fabric having its circumferenceattached to the lower end of said body portion-by a seam whereby saidseam does not interfere with the lower central portion of thesemispherical closed end. a

In testimony whereof, I have signed my name to this specification in thepresence of two subscribing witnesses, this 18th day of January, 1910.

CHARLES KNOX HARDING.

Witnesses:

NANETTA L. MCOALL, LEONOBE FRANKENSTEIN.

